WINTER VEGETATION NEAR LIMA. 71 



sea-bottom extends for a distance of fully fifteen 

 miles from Lima into the valley of the Rimac, which, 

 in approaching the coast, gradually spreads out from 

 a narrow gorge to a wide valley with a flat floor. At 

 the same time the river gradually dwindles from a 

 copious rushing torrent to a meagre stream, running 

 in many shallow channels over a broad stony bed, 

 until it is finally almost lost in the marshes near 

 Callao. Its waters are consumed by the numerous 

 irrigation channels ; for it must be remembered that 

 along the western side of the continent, for a distance 

 of nearly thirty degrees of latitude, cultivation is con- 

 fined to those tracts which can be irrigated by streams 

 from the Andes. Keeping pretty near to the left 

 bank of the Rimac, the railway runs between two 

 detached hills, formerly islands when the sea stood a 

 few hundred feet above its present level. That on 

 the north side is called the Amancais, and another 

 less extensive mass rises south of the river. 



Throughout the greater part of the year these hills, 

 as well as the lower slopes of the Cordillera, appear, 

 as they did to me, absolutely bare of vegetation ; but 

 in winter, from June to September, slight showers of 

 rain are not unfrequent, and the fogs, denser than in 

 other seasons, rest more constantly on the hills, and 

 doubtless deposit abundant night-dews on the surface. 

 The seeds and bulbs and rhizomes awake from their 

 long sleep, and in a few days the slopes are covered 

 with a brilliant carpet, in which bright flowers of 

 various species follow each other in rapid succession. 



Alongside of the railway runs a broad road covered 

 to a depth of a couple of feet with volcanic sand, with 



